This is a protocol for people with newly diagnosed Standard Risk Acute Lymphoblastic Leukemia. The study is broken up into parts. Each part of the study will be exploring different phases of chemotherapy such as Induction, Post-Induction, and Maintenance. In each phase of the study, researchers will be testing different experimental drug regimens versus standard treatments to see which one works better. Additionally, participants will be grouped based on their risk level and may receive different chemotherapy regimens based on their risk.

Inclusion Criteria

Exclusion Criteria

Patients who have received prior cytotoxic therapy except for steroids or intrathecal chemotherapy

Patients who have secondary ALL that developed after treatment of a prior malignancy with cytotoxic chemotherapy

Study Requirements

All eligible and consenting participants will receive standard Induction therapy and information will be collected about the effects of drug regimen.

Participants will then be assigned post-induction phase regimen as follows:

All participants with Down Syndrome Standard Risk ALL will receive standard treatment. Information will be collected regarding disease outcomes and the effects of standard treatment.

All participants with Average-Risk ALL will receive standard therapy until the Maintenance phase. Participants will then be randomized to one of four Maintenance arms. which involve varying the dose and frequency of standard drugs.

All participants with Low-Risk ALL will be randomized to one of two post-Induction arms.

The length of participation in this trial will be 1 to 2 years, depending on which post-induction therapy is assigned. Participants will be followed for up to 10 years.